BB Vital Statistics

Raam

When purchasing a new BB and Crankset, what are the vital measurements/information that I need to know?

BB Thread: how do I determine if I have English or Italian?
Do I need to know BB width and diameter?
Apart from crank length, do I need to know anything else about the crankset? Thinking of going for a Miche track one.

Am I missing anything?

TinyExplosions

Raam wrote: »

When purchasing a new BB and Crankset, what are the vital measurements/information that I need to know?

BB Thread: how do I determine if I have English or Italian?
Do I need to know BB width and diameter?
Apart from crank length, do I need to know anything else about the crankset? Thinking of going for a Miche track one.

Am I missing anything?

Look at the way that the original one threaded in, if one side is the reverse of the other, it's English, if they both go in the same way, Italian.

BB width and diameter is standard, it's only the threading to worry about.

Only other concern is axle length, but if you're going for the Miche, it's 107mm, and should work ok with a sugino or miche crankset

biker_joe

typically, Italian thread BB shells are 70mm and English ones are 68mm...
So the BB width ( or shell size ) is not standard I'm afraid !!

Spinal length is typically 108mm for a double and 113 for a triple chainset...


Been lookin at all this cos I just ordered an ISIS FSA bottom bracket for an FSA carbon TT crankset .... Italian double ( 70mm x 108mm )

Raam

For what it's worth, the bike only had one chainring (it's very old) and I'll be putting a track chainring on in place of it.

TinyExplosions

biker_joe wrote: »

typically, Italian thread BB shells are 70mm and English ones are 68mm...
So the BB width ( or shell size ) is not standard I'm afraid !!

Yes, I should have clarified that Italian thread and English thread are different standards, but within that they'll be the same, if that makes sense?

ie, any english thread BB will fit in any English threaded shell, and vice versa for Italian

Raam

So once I know my thread, I don't need to be concerned with any other measurement?

TinyExplosions

Raam wrote: »

So once I know my thread, I don't need to be concerned with any other measurement?

Well, the only other one to worry about is spindle length, but if you're putting a track crank on, I'd say the Miche one at 107mm is just fine (it has a couple mm adjustment on it anyway to get chainline bang on). If you're going for a Campag crankset, get a campag BB

Raam

TinyExplosions wrote: »

Well, the only other one to worry about is spindle length, but if you're putting a track crank on, I'd say the Miche one at 107mm is just fine (it has a couple mm adjustment on it anyway to get chainline bang on). If you're going for a Campag crankset, get a campag BB

I'm going for a Miche crankset, or the cheapest I can find. Spindle length?

niceonetom

If it's for that really old frame you got from tonto, the threading might have a different tpi. 24tpi as opposed to 26tpi or something? Can't remember off the top of my head, but it can be an issue with truly venerable frames.

check that out before you go shopping.

TinyExplosions

Raam wrote: »

I'm going for a Miche crankset, or the cheapest I can find. Spindle length?

the 107mm Miche BB should be fine then

scottreynolds

Raam wrote: »

So once I know my thread, I don't need to be concerned with any other measurement?

Based on the age of the bike I say your most likely using a old standard. The bike is circa 1960's and I'm not sure when the British and Italian standards were introduced. Either way, once your painted up and ready to go take your biike to the cycle super store, there's a nice german guy there, and they'll rethread the bb. They did this for me on the Hack bike in 5 minutes after the internet company I bought parts off stuffed up and sent me the wrong bb cups. Oh yes, twas free like the kit-kat.

I was thinking about getting this crankset and grinding the teeth off the big ring like somone else done.

http://www.chainreactioncycles.com/Models.aspx?ModelID=11831

Raam

Hmm, back to square one, it seems...

rottenhat

Raam wrote: »

Hmm, back to square one, it seems...

but wait, nobody's even mentioned the rarer French and Swiss (okay, I might be imagining that one) threadings....

jeffontour

Raam wrote: »

Hmm, back to square one, it seems...

This is where you use your Lidls Finest calipers and confirm what the tpi is on the BB we took out!

scottreynolds

rottenhat wrote: »

but wait, nobody's even mentioned the rarer French and Swiss (okay, I might be imagining that one) threadings....

no no -- your correct.... Swiss was no doubt to exact to be practical for the others

http://sheldonbrown.com/tooltips/bbcups.html

To remove a right threaded fixed cup (French or Italian), tighten the bolt with the socket wrench from the inside of the bottom bracket, holding the nut with the box wrench. Once the bolt is as tight as can be, keep on tightening it, until the cup screws itself out. Once the cup starts to move, turn both wrenches together.

To remove a left threaded (British or Swiss) fixed cup, hold the bolt with the socket wrench and turn the nut with the box wrench.

blorg

The modern BSA (Birmingham Small Arms) British bottom bracket standard predates WW2, although Raleigh were a holdout with their own standard until the 1990s. If it is a British bike from the 60s I would imagine you have a fair chance it is the modern standard although you would have to check.

Here is the list of standards from Sheldon.

Raam

Clear as mud now

scottreynolds

Raam wrote: »

Clear as mud now

Just take it out -- have you got that far yet? If you have just take it into your friends at cycological and ask them. They'll just try it out on one of there frames and tell you immediately what type it is.

Raam

scottreynolds wrote: »

Just take it out -- have you got that far yet? If you have just take it into your friends at cycological and ask them. They'll just try it out on one of there frames and tell you immediately what type it is.

yeah it's out

TinyExplosions

Raam wrote: »

yeah it's out

and did it unscrew the same direction on both sides, or was one opposite the other (ie, you turned one side CW, and the other CCW to loosen)?

scottreynolds

TinyExplosions wrote: »

and did it unscrew the same direction on both sides, or was one opposite the other (ie, you turned one side CW, and the other CCW to loosen)?

If you can't remember -- screw it back in and remove